1. Field of the Invention
The present invention relates to an imaging apparatus, an imaging system, and an image processing method.
2. Description of the Related Art
In a general imaging apparatus, an optical image of a subject is formed on an image pickup device via an optical system. In such an imaging apparatus, the light amount of the optical image formed on the image pickup device becomes smaller in parts closer to the periphery of the image pickup device because of the characteristics of the optical system. Moreover, in such an imaging apparatus, the optical image is more distorted in parts closer to the periphery of the image pickup device. Heretofore, a shading correction has been performed to correct the decrease of the light amount in the peripheral parts of the image pickup device, and a distortion correction has been performed to correct the distortion of the optical image resulting from the characteristics of the optical system.
Here, when the image deterioration is corrected by use of the shading correction or the distortion correction, the S/N characteristics may vary between the center and periphery of the image. In contrast, Jpn. Pat. Appln. KOKAI Publication No. 2006-295807 suggests the suppression of the variation of the S/N characteristics between the center and periphery of the image by controlling the suppression level of noise reduction in accordance with a correction amount used in, for example, the shading correction.